This invention relates to the art of sensing the electrical conductivity of fluid, and more particularly to a new and improved apparatus for sensing and signalling the presence of liquid having a predetermined electrical conductivity.
One area of use of the present invention is detonating an electro explosive device of a release mechanism for uncoupling a parachute canopy from its load upon landing in water, although the principles of the present invention can be variously applied. In the design of such release mechanisms it is obviously important to provide against accidental detonation. Prior art release mechanisms operate when the sensors thereof are immersed in a body of water but many prior art arrangements are susceptible to false detonation when exposed to rain, salt water spray and fog. It would, therefore, be highly desirable to provide fluid conductivity sensing apparatus for providing a signal when exposed to fluid of a predetermined minimum conductivity but which provides no such signal when exposed to rain, salt water spray, fog and similar conditions.